Poly(aryl ethers) have been known for about two decades; they are tough linear polymers that possess a number of attractive features such as excellent high temperature resistance, good electrical properties, and very good hydrolytic stability. Two poly(aryl ethers) are commercially available. A poly(aryl ether sulfone) is available from Imperial Chemical Industries Limited. It has the formula (1) ##STR1## and is produced by polycondensation of 4,4'-dihydroxydiphenyl sulfone with 4,4'-dichlorodiphenyl sulfone as described in, for example, Canadian Pat. No. 847,963. The polymer contains no aliphatic moieties and has a heat deflection temperature of approximately 210.degree. C. Another commercial poly(aryl ether) is available from Amoco Performance Products, Inc. under the trademark UDEL.RTM.. It corresponds to formula (2) and has a heat deflection temperature of about 180.degree. C.
A closely related class of polymers, i.e., those wherein the sulfone group is partially or totally replaced by a keto group, is also known. The poly(aryl ether ketones) are engineering polymers that are highly crystalline [as opposed to the amorphous nature of (1) and (2)] with melting points above 300.degree. C. Two of these crystalline poly(aryl ether ketones) are commercially available and are of the following structure: ##STR2##
Over the years, there has been developed a substantial body of patent and other literature directed to the formation and properties of poly(aryl ethers) (hereinafter called "PAE"). Some of the earliest work such as by Bonner, U.S. Pat. No. 3,065,205, involves the electrophillic aromatic substitution (viz. Friedel-Crafts catalyzed) reaction of aromatic diacylhalides with unsubstituted aromatic compounds such as diphenyl ether. The evolution of this class to a much broader range of PAEs was achieved by Johnson et al., Journal of Polymer Science, A-1, Vol. 5, 1967, pp. 2415-2427; Johnson et al., U.S. Pat. Nos. 4,108,837 and 4,175,175. Johnson et al. show that a very broad range of PAEs can be formed by the nucleophillic aroatic substitution (condensation) reaction of an activated aromatic dihalide and an aromatic diol. By this method, Johnson et al. created a host of new PAEs including a broad class of poly(aryl ether ketones) (hereinafter called PAEK's).
In recent years, there has developed a growing interest in PAEK's as evidenced by Dahl, U.S. Pat. Nos. 3,953,400; Dahl et al., 3,956,240; Dahl, 4,247,682; Rose et al., 4,320,224; Maresca, 4,339,568; Attwood et al., Polymer, 1981, Vol 22, August, pp. 1096-1103; Blundell et al., Polymer, 1983, Vol 24, Aug. pp. 953-958; AttWood et al., Polymer Preprints, 20, No. 1, April 1979, pp. 191-194; and Rueda et al., Polymer Communications, 1983, Vol 24, September, pp. 258-260. In early to mid-1970, Raychem Corp. commercially introduced a PAEK called STILAN, a polymer whose acronym is PEK, each ether and keto group being separated by 1,4-phenylene units. In 1978, Imperial Chemical Industries PLC (ICI) commerciallized a PAEK under the trademark Victrex PEEK. As PAEK is the acronym of poly(aryl ether ketone), PEEK is the acronym of poly(ether ether ketone) in which the phenylene units in the structure are assumed.
Thus, both the poly(aryl ether sulfones) and the poly(aryl ether ketone) polymers are well known. They can be synthesized from a variety of starting materials; they show a wide range of glass transition (Tg) and melting (T.sub.m) temperatures. They are tough materials and have a potential for a wide variety of uses; their favorable properties class them in the upper bracket of engineering polymers.
As mentioned before, two of the most widely used preparative poly(aryl ether sulfone) and poly(aryl ether ketone) methods are the nucleophilic polycondensation, involving activated dihalobenzenoid compounds and bisphenoxides; and the electrophilic (Friedel-Crafts) route, such as the reaction of diacyl halides with aromatic reaction of diacyl halides with aromatic hydrocarbons, catalyzed by a Lewis acid. Two additional routes were described in the literature. The first of these is the Ullman polymerization; thus, the self-condensation of sodium p-bromophenoxide to poly(1,4-phenylene oxide) is claimed in U.S. Pat. No. 3,220,910; a cuprous chloride/pyridine complex was used as the catalyst: ##STR3##
The reaction of equation was also investigated by vanDort et al., European Polymer Journal, Vol. 4, pp. 275-287 (1968); and by Jurek and McGrath, Am. Chem. Soc., Div. Polymer Chemistry, Preprints, Vol. 28, No. 1, pp. 180-182 (1987). Linear polyarylene polyethers composed of recurring units having the formula ##STR4## and prepared via the Ullman route, are described in U.S. Pat. No. 3,332,909. In formula (7) G is the desiduum of a dihydric phenol selected from the group consisting of ##STR5## wherein R represents a bond between aromatic carbon atoms, --O--, --S--, --S--S, or a divalent hydrocarbon radical having from 1 to 18 carbon atoms inclusive; and G' is the residuum of a dibromo or diiodobenzenoid compound selected from the group consisting of ##STR6## wherein R' represents a bond between aromatic carbon atoms, --O--, --S--, --S--S--, or a divalent hydrocarbon radical having from 1 to 18 carbon atoms inclusive; with the provisos that when R is --O--, R' is other than --O--; when G is (8), G' is (10); and when G' is (8), G is (9). The polyarylene polyethers were claimed to possess excellent physical properties and thermal, oxidative, and chemical stability.
Poly(aryl ethers) of a somewhat similar structure, were disclosed in European Patent Application No. 222,536. These latter polymers were also prepared via the Ullman polycondensation.
Poly(aryl ether) polymers were also prepared by the nickel catalyzed coupling of aryl polyhalides as described in U.S. Pat. No. 4,400,499. The coupling reaction is performed in the presence of a reducing metal selected from the group consisting of zinc, magnesium and manganese or mixtures thereof, and in a liquid phase of an aprotic solvent under substantially anhydrous conditions. The catalyst comprises a nickel compound and at least one ligand such as triarylphosphine; and an aromatic bidentate compound containing at least one ring nitrogen atom. High molecular weight poly(aryl ethers) were obtained via this route.